Composite panel



Jan. 29, 'R v CLEEF COMPOSITE i=ANEL Filed Jap. 29, 1941 fixa-Z151..

vv'i J, NiTED"v STATES PATENT oFF-ICE f f 2,393,843"y j u Y COMPOSITE PANEL" 1 e Y A Paul van clef, chicago, 111., assignartby mesmeV assignmentato Van (lleeil Bros.; Chicago, lll., a partnership composed of Noah Van cleref,

l Y* i l Felix Van Cleef, Paul Van'fCleei, Frances G. i` Y i Van Cleef, Ruth Van Cleef, and Jeanne Van .Y Cleef Y 2 Claims.

The' present invention relates generally to panelsjMore particularly the invention relates to that type' of panel which is used instead of veneer a'sacovering for a' wall or one of the surfaces of asplece of furniture, such for example, as a deskorbed.

' 1It hasjheretofore .been proposed to employ or use as apanel of the aforementioned type a thin sheet of synthetic resin of the phenol-formaldehyde' variety ory the urea-formaldehyde variety. Such'a panelisin most instances applied by Way oan" adhesive to the Work surface and when in placefserves as an ornamental or nish type cover'ing. Inpracticeit has been found that a panel of the type under consideration, although it eiectively-and-.eiliciently serves its intended purpose, is subject to-certain objections. l In the first place, sucha panel is so brittle and fragile that it often cra cl s or breaks during transportation to the placeg'of applicationor in connection with applicationto the work surface. Secondly, it is difficulttorrbondthe panelsto the Work surface because its 'inner face is smooth and hence the adhesive used in connection with application does not readily adherey to it. Thirdly, any small projections or surfacev irregularities on the Work surface disturb the smoothness of the outer face ofthe panel. 1

The primary object of this invention is to provide a panel which is an improvement upon, and eliminates the defects of, previously designed panels of the sameg'eneral type or character by reason of the fact that it is of composite design andcomprises in addition to the sheet of synthetic resin a comparatively thin backing sheet which is formed of a homogeneous tmixture of ground cork and vulcanized rubber and is cemented to the inner face of the main orprincipal sheet. By employing a backing sheet of this type the sheet of synthetic resin is so Vreinforced Y or vstrengthened that it is not likely to crack or ruptureY during transportation tothe place of installation orA application to the work surface. Another advantage of employing a Vbacking sheet in the form of a homogeneous mixture of ground corkv andrubber resides in the fact that the panel as a whole may be readily mounted or secured in-,place because of the aflinity of the backing sheet for the adhesive'vvhichis used to secure the composite `panel to the Work surface. A further advantage resides in the fact that such a backingsheet is compressible or plastic to a certain extent and hence absorbs or accommodates any minuteror small projections or irregularities on the work surface and thus eliminates uneven- Application January 29, 19%11,Y serial No. 376,429 (ci.

ness in the outer face of the sheet of synthetic resin.vv lA still further advantage of employing a backing sheet of the typejhere under consideration resides in the fact that the panel as a Whole, i. e., the composite 4panel, has sound deadenlng properties kdue to the resiliency 'of the backing sheet.

Another object 0f the invention is to provide a compositepanel of the last mentioned type and character in which the back face of the backing sheet is provided with certain irregularities or unevenness dueto the method by which the backingsheet is madekand hence has a marked `or pronounced laffinity for the adhesive for securing the panel to the worksurface.

A further object of the invention is to provide a composite'panel which is generally an improvement in the artand not only has novel characteristics or properties Ibut also'may be manufactured at a low and reasonable cost.v

Otherl obects of the invention and the various advantages and characteristics of the present composite panel will beapparent from a consideration of the following detailed description.

The invention consists 'in the several novel features which are hereinafter set'forth and are more particularly dened by claims at the conclusion hereof. l

.In the-drawing whichaccompanies and forms a part of this specification.ordisclosure and in which likeletters and numerals of reference denoteA correspondingA parts throughout the several views:

Figurel is a front perspective view of a composite panel embodying the invention;

' Figure 2 isa 'rear perspective View showing in detail the surface irregularities of the back face of the cork-vulcanized rubber backing sheet;

Figure 3 is a section showing the material of which the backingv sheet is formed, prior to vulcanization of the rubber'content and after it has been calendered onto a fabric liner;

Figure 4 is a section showing the backing sheet afterremoval of the ,fabric liner at the conclusion ofthe vulcanizing operation and after application to its calendered or front face of a plurality of coats of dry type rubber-rosin cement; and

vrFigure 5 is a section showing the backing sheet and the sheet of synthetic resin in a steam heated press and being subjected to the action of heat and pressure for purposes of cementing or bonding. them together.

The panelwhich is shown in Figures 1 and 2 of the drawing constitutes the preferredform'or embodiment of the invention. It is designed to be used as a covering for a wall or other surface and as its parts comprises a backing sheet '6, a cement coating 1 and an outeror finish sheet 8.

`The backing sheet is formed for the most part of ground cork and vulcanized rubber, as hereinafter described, .and is. united or biondedv to. the rear or innerface; ofgthe iinishsheet 8- by'way of the cement coating 1. It has a four-fold purpose in that it serves-(a) to reenforce or strengthen the brittle finish sheetl 8 and thus prevent cracking or rupturing of the latter; thlliioy composite panel to act as a sound or noise ab-v sorbing medium. The backing sheet 6 maybe of any desired thickness. For practical purposes it hasbeen found that if the backingy sheet has a thickness lof 1 approximately al; of an inch it is both. suitableand economical andaffords the ni'shsheet 8 an efficient andy effective backing. Thei'lnish sheet B is formed of synthetic resin of any of the varieties which are now on the market or. obtainable, such as the. phenol-formaldehyde variety (Bakelite) and. the urea-formaldehyde variety. It preferably has a thickness of approximately 1/64 of an inch and is so formed that the outer face thereof` is shiny or glossy while its inner or rear face is dull. Sheets or layers (not shown) of paper are embedded in the backing sheet for purposes of reinforcement. So far as the composite panel as a wholeis yconcerned the finish sheet awhenin its operative position serves as an ornamental nish type covering. In installing thepanelany suitable adhesive isv applied to the rear face of the backing sheet 6 and the panel is thenpressedV against the Work surface. Upon hardeningA or setting. of the adhesive the panel is bonded to the surface and remains securely in place.

The backing sheet 6. of the. panel is formed of y the following ingredients in substantially the p'roportions set forth:

Crude rubber pounds In forming thebacking sheet the crude rubber is broken down by milling it. Thereafter the mineraliiller, sulphur and accelerator are added to themilled rubber. e After mixing together the rubber, mineral filler, sulphur and accelerator` the ground cork 'is added to, `and worked into, the mixture. In practice ithas been found that the best results `have been obtainedA when the cork has a mesh running from 16 to 30. The milling or mixing operation causes or effects a uniform distribution of the cork particles throughout the rubber. vWith cork particles having a mesh no greater .than 16 and no less than 30 the resultant sheet has. .the desired or proper texture. After proper mixing of the aforementioned ingredients the material is calendered onto anon-sticking cr non-adhesive liner 9 of linen,.cotton, or like textile fabric. As .well understood in the art the calendering roll is set so as to calenderthe materialontothe liner so that it has fthe' desired depth or thickness. VAfter the calendering operation .the material and the fabric liner are placed in an oven or dry heat vulcanizer for a suilicient period of time to effect complete cure or vulcanizatlon of the rubber part or content of the material. After the vulcanizing step the ground cork and vulcanized rubber mixture or material is in its final or completed form and constitutes the backing sheet, 6. The fabric liner `9 does not: form any part of the composite panel. It is merely used in connection with the formation or fabrication of vthe backing sheet B. When the material from whichV the backing sheet 6 is formed is calendered onto the liner 9 the face in contact with the liner, i, e., the back face of the material shows the impressions of the liner. In other words the back face of the sheet 6 simulates the surface contour ofthe liner due to thev fact that the warp Y and Woof of the liner become embedded in the plastic material. The back face of the sheet, upon removal of the liner, is pronouncedly irregular (see Figure 2) and hence it has an extremely great affinity for the adhesive which is used in securing the panel in place. The backing sheet is pliable as well as resilient due to the fact that Pounds Rubber (inner tube reclaim) 39 Zinc oxide or other mineral filler 39 Wood rosin 39 Slaked lime 2 The aforementioned ingredients are milled or mixed together and then dissolved in approximately 35 gallons of rubber solvent, such as naphtha. After spreading of two or more coats of the composition on the front face of the backing sheet (iv the solvent is permitted to evaporate. The cement type mass or material remaining after evaporation of the solvent constitutes the cement coating 1. Such coating is essentially a dry type rubber-resin cement which is capable of being energized by heat and pressure.

After application of the coating 1 of cement type material to `the inner face of the backing sheet 6 the facing or lfinish sheet 8 is united or bonded to the sheet 6 by way of the coating. This is accomplished by placing the finish sheet so that the rear or dull face thereof is in contact with the coating 1. Thereafter the two sheets are placed in a press P as illustrated in Figure 5. 'Ihe press P is illustrated in a diagrammatic manner and consists of a platen-type stationary member p and a platen-type movable member p1. The stationary member p has a continuous duct p3 through which steam is adapted to be circulated for heating purposes. The member p1 of the press P is movable vertically to and from the stationary member by way of a screw p4 or other power type raising and lowering device and has a continuous steam duct p5 therein. It is contemplated that the members p and p1 of the press be steam heated to a temperature of approximately 150 F. before the cement coated backing sheet 6 and the finish sheet 8 of synof the press is lowered by proper manipulation of the screw p4 and is forced by the latter downwards in order to exert the proper or desired amount of pressure on the two sheets. While the sheets are under pressure in the press the heat softens the cement and makes it tacky and the pressure which is exerted by the movable member p1 of the press causes adhesion of the finish sheet 8 and the coating. Ordinarily the two. sheets will be effectively and efficiently bonded together by the coating if permitted to remain in the heated press for a period of approximately five minutes. At the end of such period the movable member p1 of the press is raised and the composite panel in its completed form is removed from the compartment p2. As soon as the panel is removed from the compartment it is in condition or readiness for use. The cement coating 1, by reason of the fact that it is formed for the most part of rubber and rosin, is slightly elastic and hence permits of ready flexing of the panel while at the same time it serves as a permanent bonding medium between the backing and finish sheets.

The backing sheet 6, the coating 1 of cement type material, andthe finish sheet 8 of synthetic resin are conterminous, as shown in Figures 1 and 2.

The herein described composite panel is both durable and practical because of the reenforcement which is provided by the ground cork-vulcanized rubber backing sheet. It is capable of being flexed to a comparatively great extent without cracking or rupture of the finish sheet 8 and is capable of absorbing sound or noise because of the resiliency of the backing sheet. The method of fabricating or manufacturing the panel is essentially a simple one and hence the panel may be produced at a low and reasonable cost.

It is to be understood that the invention is not t be restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. As a new article of manufacture, a composite panel adapted to be adhesively connected to, and to serve as a cover for, a wall or other work surface and comprising a front finish sheet formed of synthetic resin, a substantially coextensive backing sheet disposed in back of the finish sheet, formed for the most part of vulcanized rubber and a slightly greater amount by weight of ground cork particles distributed substantially uniformly throughout the rubber and having a mesh running from 16 to 30, and embodying an adhesive receiving rear face with a contour simulating textile fabric, and a coating of flexible and elastic rubber-rosin cement between the two sheets and serving permanently to bond the latter together.

2. As a new article of manufacture, a composite panel adapted to be adhesively connected to, and to serve as a cover for, a wall or other work surface and comprising a thin front sheet formed of synthetic resin and having a smooth glossy outer face and a dull or rough inner face, a thicker substantially coextensive backing sheet disposed in'back of the finish sheet, formed for the most part of vulcanized rubber and a slightly greater amount by weight of ground cork particles distributed substantially uniformly throughout the rubber and having a mesh running from 16 to 30, and embodying an adhesive receiving rear face with a contour .simulating textile fabric, and a coating of flexible and elastic rubber-rosin cement between the two sheets and serving permanently to bond the latter together.

PAUL VAN CLEEF. 

